The U.S. Preventive Services Task Force recently updated their recommendations for colorectal cancer screening. The group now advises people to start screening for colorectal cancer starting at age 45. The previous recommendations suggested screening beginning at age 50.
“Rates of colorectal cancer in people over the age of 50 have been steadily decreasing, which the medical community attributes to more people being screened,” said General Surgeon David Larsen, MD, from Samaritan Pacific Communities Hospital. “However, at the same time there has been an increase in the number of people under the age of 50 who are developing colorectal cancer. It’s notable because we historically haven’t been looking for it in people that young.”
What Is a Polyp?
A polyp is a small growth that can form in the colon and rectum. Most of the time polyps are benign and don’t cause any problems, but if colorectal cancer is going to develop, it usually grows in these polyps.
By age 50, the American Cancer Society estimates about half of people who have a colonoscopy have developed polyps. According to Dr. Larsen, reducing the screening age can help detect colorectal cancer early, when it’s most treatable.
Colonoscopy & Other Screening Options
Screening for colorectal cancer can be conducted through a visual exam of the colon or by testing a stool sample. You’ve probably heard of a colonoscopy, but there are several different types of colorectal cancer screenings.
Visual Exam Options
Visual exams look at the colon for pre-cancerous polyps. These polyps are then removed. Your primary care provider can refer you to a surgeon for a visual exam.
Colonoscopy is the most thorough of the screening options. Your surgeon examines the entire colon and rectum and can remove polyps if necessary. Unless there is something that your doctor is concerned about, you only need a colonoscopy every 10 years.
Flexible sigmoidoscopy is similar to a colonoscopy, but the surgeon examines only the lower third of the colon. Minimal bowel preparation is needed. Polyps can be removed if they are not too large. Recommended every five years.
CT colonoscopy uses a CT scan of the entire colon to look for polyps. Bowel cleaning is necessary, like for a colonoscopy. If polyps are found you will need to have a colonoscopy to have them removed. Recommended every five years.
Stool-based Test Options
Stool-based tests work by detecting cancer rather than polyps. Most tumors bleed a little, and these tests find colorectal cancer by detecting small amounts of blood in the stool. Tests can be ordered by your primary care provider through a local lab. If the test comes back positive for cancer, you will need a colonoscopy to remove the cancer tumor.
Multitargeted DNA test, manufactured by Cologuard, requires one stool sample. Detects blood in stool and genetic material related to colorectal cancer. Recommended every three years.
Highly sensitive fecal immunochemical test (FIT) and highly sensitive guaiac-based fecal occult blood test (gFOBT) both require several stool samples. Recommended every year.
Which Test Is Right for You?
There are pros and cons to each type of test regarding cost, time, discomfort and accuracy.
“A colonoscopy is the gold standard in terms of finding and treating pre-cancerous polyps, because we can find and remove any potentially cancerous growths immediately,” Dr. Larsen said.
However, he encourages using whatever test you feel comfortable with.
“Because colorectal cancer grows slowly for average-risk individuals, regular screening can catch most cancers before it becomes a problem,” said Dr. Larsen. “The best test is the one you will complete.”
Learn more about colorectal cancer in our health library.